The next U.S. attorney general is going to have to respect the decision of Colorado and other states to legalize recreational and medical marijuana — at least if Republican Sen. Cory Gardner has his way.

“Whoever comes after him is going to face some pretty tough questions about where they stand on states’ rights and making sure they will stand up for states’ rights,” Gardner told The Denver Post on Thursday. “I am going to demand that the new attorney general side with the president because the president is right on states’ rights.”

Gardner blocked President Donald Trump’s nominees to the Justice Department for three months in early 2018 after Attorney General Jeff Sessions rescinded something called the Cole Memorandum, an Obama-era policy that outlined a set of rules for states that legalized marijuana to follow if they wanted to avoid federal intervention.